The nurse explains to a student nurse that the median lethal dose of drugs is often determined in laboratory preclinical trials. Which rationales best support why this is done?

Question

1. It would be unethical to determine these values in human subjects.
2. The safety of the medication must be determined prior to clinical trials.
3. It is difficult to obtain sufficient participants for clinical trials.
4. Clinical trials determine only the effective dose of a drug.
5. It is too costly to conduct the studies during clinical trials.

Answer 1

Correct Answer: 1,2
Rationale 1: Laboratory animals are used in clinical trials to determine the LD50, or the dose that kills 50% of the subjects. It would be unethical to kill human subjects.
Rationale 2: Before a drug is released for trials in human subjects, its safety must be determined.
Rationale 3: It can be challenging to obtain sufficient subjects at times, but this is not the reason for doing lethal studies during preclinical trials.
Rationale 4: Clinical trials determine not only the effectiveness of a drug, but also its adverse and toxic effects.
Rationale 5: The cost of the trials is the reason they are conducted with animal subjects.
Global Rationale: Laboratory animals are used in clinical trials to determine the LD50, or the dose that kills 50% of the subjects. It would be unethical to kill human subjects. Before a drug is released for trials in human subjects, its safety must be determined. It can be challenging to obtain sufficient subjects at times, but this is not the reason for doing lethal studies during preclinical trials. Clinical trials determine not only the effectiveness of a drug, but also its adverse and toxic effects. The cost of the trials is the reason they are conducted with animal subjects.